Radio-frequency switch



May 30, 1950 N. E. KLEIN RADIO FREQUENCY SWITCH 4 Sheets-Sheet 1 Filed Oct. 31, 1945 INVENTOR. Norman E. /1/em BY Wk.

ATTORNEY y 1950 N. E. KLEIN 2,509,928

RADID FREQUENCY SWITCH Filed Oct. 31, 1945 4 Sheets-Sheet 2 IN V EN TOR.

wi w W ATTORNI Y May 30, 1950 v N. E. KLEIN 2,509,928

RADIO FREQUENCY SWITCH Filed Oct. :51, 1945 4 Sheets-Sheet s INVENTOR. Norma/2 t. Mam

ATTORNEY May 36, .1950 N. E. KLEIN 2,509,928

RADIO FREQUENCY swrrca Filed Oct. 51, 1945 4 Sheets-Sheet 4 Ila INVENTOR. Norma/7 E K /e//1 A T TOFNEY Patented May 30, 1950 UNITED STATES PATENT OFFICE RADIO-FREQUENCY SWITCH Application October 31, 1945, Serial No. 625,886

4 Claims.

This invention relates to selector switches, and more particularly to radio-frequency switches.

An object of this invention is to provide an indexible selector switch for making improved contact in the selected position.

Another object is to provide an ultra-high-frequency coaxial selector switch.

A further object is to provide an improved remote control mechanism for the improved selector switch.

According to the invention, a cylindrical selector contact is indexed from one contact position to the others, progressively. It is retracted radially preparatory to each indexing motion and in each selected position it is projected radially to establish a firm contact with the selected terminal, and also to grip the conductor along which it slides radially. When used for ultra-high-frequency circuits for which the arrangement is particularly well suited, the cylindrical contact is associated with an inner coaxial conductor. A remote-control mechanism is provided for indexing the switch to any given position and the improved control mechanism forms an integral part of the novel selector switch. The details of the invention, together with further novel features, will be apparent from the following specific disclosure of one embodiment thereof, in which:

Fig. 1 is a lateral external view;

Fig. 2 is an end view in the direction 2-2 of Fig. 1 when the two main casing sections are separated and the assembly is rotated about its longitudinal axis through approximately a right angle;

Fig. 3 is an end view in the direction 33 of Fig. 1 when the two main casing sections are separated and the assembly is rotated through substantially a right angle;

Fig. 4 is a lateral section along the axis of the switch in a plane parallel to Fig. 1 with the assembly rotated through approximately 180 degrees;

Fig. 5 is a sectional view along the line 55 in Fig. 4, With the parts in a configuration assumed during indexing;

Fig. 6 is a sub-assembly of the radially movable contact, associated with parts of its operating mechanism; and

Fig. 7 isa wiring diagram of the remote control mechanism.

In Fig. 1, a switch casing is shown divided into an upper part or section III and a lower, generally hexagonal part or section l2. The upper casing section is secured by means of screws it through flange 16 to lower casing section 12.-

Connector IE on section it contains multiple terminals for the remote-control circuit to be described. Casing I2 has an axial terminal 20 which is adapted to be connected to any one of the four radial terminals 22 with which the switch is provided. Cover plates 24 are provided in two of the six possible positions in casing l2 where terminals 22 might be mounted if required. The hexagonal form of casing i2 is purely illustrative, of course, and as many selector positions as desired can be incorporated in a switch made in accordance with the present invention.

Upper casing section I ll encloses the motordrive mechanism, reduction gearing and part of the remote-control switching system. Lower section [2 carries the R,.-F. selector mechanism and more of the remote-control mechanism. Sections it) and i2 can be separated upon removal of screws l4, and when this is done, the inside views of sections l0 and I2 appear as in Fig. 2 and 3. (Fig. 3 shows two of the four terminals 22 replaced by cover plates 24.) In Fig. 3, radially movable selector contact 26 is shown in engagement with one of the terminals 22. Detent 28, which is rigidly associated with that contact 25, fits somewhat loosely within any of aligning notches 30 (Fig. 2) in ring 3! secured to casing section In. (In Fig. 2 only four of the twelve screws intended to secure ring 3! to casing it are shown.) There is one notch 3G for each selector-switch position 22 or 24. Detent 28 is Withdrawn from notch 30 as slotted contact member 26 is radially withdrawn preparatory to each indexing operation.

Ihe radial withdrawing motion and the indexing motion are acomplishecl by mechanism to be described, driven by the motor and reduction gearing in casing Hi. In Fig. 2, pinion 32 isshown in mesh with gear 34 and the latter is connected by splined shaft 36 (Fig. 3) to the mechanism in lower casing 12. Axially resilient contacts 38 are adapted intermittently to make electrical contact with segments 44 and 46, and leafspring contacts 42 and 4!! of casing section H3 (Fig. 2) are adapted to maintain continuous electrical contact with contact segment 46 and slip ring 48, respectively, of section l2. These contacts and segments form part of the remote-control mechanism to be described. Casing I2 has a flange 52 by means of which the switch can be attached to any convenient support.

In Fig. 4, axial terminal 20 is shown connected to One of the radial terminals 22 through radial selector contact 26, conical-ended element 54, and other intervening parts to be described.

Each terminal 22 has an inner coaxial conductor 56 for connection to the inner conductor of a coax line. A tongue 58 is suitably formed on each inner conductor 59 and this is wedged within forked inner, coaxial conductor 69 of the selector assembly as the selector rotates into the selected position. At right angles to inner conductor tlland coaxial with terminal 29is another inner coaxial conductor 52, formed with a neckeddown, split end 6| fitting tightly within hole 63 in inner conductor 69. Each of the inner conductors t, 60 and 62 are held in placebysuit able dielectric material as shown. Dielectric portion 55 surrounds the stationary conductor 62 and is indexed with conductor 69 by WhlClfllt is penetrated. The dielectric portion M in each terminal 22 has a shallow spherical conpayity and the dielectric sleeve 66 surrounding conductor 69 is spherical-ended for uniform but close space ing from dielectric portion 64. There is a slot in the end of sleeve .66 to passelements 58,..dur-

ing rotation and the axial bore of. thesleeve is.

enlarged as .at E1 to allow. the forked portions of conductorfifl to spread, Metallic cylinder 63 encases. sleeve 65 and. forms a radial slide-bearing for contact 26..

Cylinder 68 is connected to element 54 by means of a transition piece lilwhich is internally cylindrical to accommodate the dielectric 65. surrounding conductor $2, and, which is squared externally. In contactwithtwo of the parallelexternal surfaces of transition piece'lt are plates. '52. At one end these plates are spaced apart and secured to plate 14 (Figs. 5 and 6) while at their opposite ends theyare equallyspaced, and secured to cylindrical contact 26, the base of which is externallysquared. Stud 19 extending through ahole in plate 14 is. rigidly supported.

by transition piece liland carries adjustable abutment in the form of nut 'lfifor compression spring.

89, the opposite end of which bears against plate 74. It is by this means that selector contact. 29 is forced outward radially for contact withthe selectedterminal 22. The cylindrical portionof Contact 25 has axial slots 79. (Figs. 5 an'dfi) and its end .83 is made cenicalto fit into a conical seat 8| of each terminal 22. The ,camming actionof the conical portionecauses contact 28 to grip cylinder 68 firmly. This camming action also centers the. selector. assembly accurately,

after the relatively rough positioning by. coaction.

88-(Fig. 5) are adapted to engagean associated, shoulder 90 of plates 72 Arms 8 8- areshown. in their normal position in Fig. 6,..while. in Fig. 5, they are shown in the partly operatedpo sition. assumed when detent 28- is. almost f ully retracted from. notchjSB; The normal position of Y1 shaped member 86; is with its third arm 92- vertical, as in,Fig. 5. Member as-is retained-in assemblywith transition piece {10. by aplate 98 screwed at three. points to extellsions Illa. of the. transition piece (Figs. 4 and..5) Plate 93 sup.

ports curved rod. [Elli by mean s of studs 5 92; and

a square spacerlt Helical springs 9d and 95 surroundrod ifllband, are,held in cornpressionbetween spacer 1M .and onset the. studsllli Arm 92 has a U-shaped notch I96 closely embracing rod Hill. Normally the arm is centered about spacer HM by springs 96 and 96, arm 92 and Spacer I94 being equal in length along rod'lllt. When arm 92 is displaced from its normal position, it compresses one of the springs 94 or 99, While the other remains confined between spacer I94 and its stud I92. Spring 89 is also compressed through coaction of an arm 38 with the radially retractable contact assembly, as described above. After detent 29 is sufficiently retracted from notch 39 as shown in Fig. 5, spring 94-acting on its stud I92 snaps plate 98, transition. piece '19, contact 26 in its retracted r position, coax elements 60, 96 and 68, dielectric portion and rigidly associated spacer H14 through an angle of approximately 20 in the embodiment shown, during which springs 94 and 96 realignrspacer I94 opposite arm 92. From that point until detent 28 reaches the next notch 39, the selector assembly is maintained in the retracted configuration, by ring 3! against which detent 28,.bears. Afterspring 94 (or 95.1 has snapped he select r s emb rqush t e s al are described, the motor. and drive gearing continues the indexing .moti on until detent ZB ,is forced by spring 89 intothe succeeding notchflil. If the motor remains ener ized; the radially isabl -as emb ust aainbe Wit dr w o pressing springs 94 (or 99) and 89. The eifect of overtravel of the motor, when tie-energized the selector assembly in completing the indexing operation, to overcome anypossible bindingaction of the mechanism, rather than to relyon the yielding motor drive through arm 92 and one of the springs 94, 96, For this purpose there is provided a plate I88 (Figs. 4 and- 6) supported on plate "14 by means of pivot H0 (Fig. 65. 'At its upper end, plate N38 has a pair of cam surfaces H2 (Fig. 5) which are adapted to coact with a depending portion H4 of Y-shaped membertt. After the contact assembly has been withdrawn and during thelast 20? travel afiected by'spring 94,0r 96, dependingiportion HA acts on cam H2;

to tip plate I98 clockwise. When arm 92' is again centered by springs 9 and 96 opposite spacer between cams I i2 is vertically aligned with portion Hi l. Spring H8 surrounding stud on platen and confined by nut I22 tips plate 198 so that portion 1 I i is embraced within notch l l6.

From this point on, so long as the selector assembly remains retractedgthe motor drive through splined shaft 36 and Y -shaped member 86-acts When detent 28 is forced carried away from portion 1'; of Y-shapedmember 89. The latter is thereby freed for the next indexing operation.

Remote control mechanism Certain portions of the remOte-rCOntrOl sy tem have. previously been described. These include. axially resilient -.contacts..38-, one allocated ;toeach .radial terminal, .leaf spring brush contacts;-

40 and 42, commutator segments 44 and 46 and slip ring 48. These parts are shown not merely in Figs. 2 and 3, as previously mentioned, but also in Figs. 4 and 7. In Fig. 4, contact segments 44 and 46 are secured (as by rivets) to insulating disc I30. Insulating disc I34 spaces elements 46 and 48 from each other and an insulating washer I36 insulates ring 48 from washer I38 and nut I40. At one point disc I30 is recessed, and commutator segment 46 and disc I34 are apertured for lead I32 connecting segment 44 and ring 48. Nut I40 is threaded to sleeve I42, which extends through discs I30, I34 and I36 and is flanged at I44, to constitute a unitary assembly of contact commutator segments 44 and 46 and ring 48. This contact segment assembly is rotatable about bushing I46 which is fixed to plate 98, the bushing in turn being rotatable relative to shaft 36. A double-acting cam, here in the form of keyhole slot I50, is formed in disc I30 (Figs. 4 and '1) and upstanding pin I52 carried by the selector contact assembly (Fig. 6) works in this keyhole slot. The transition II between the large and small keyhole portions is advantageously at an angle of 30 to the radius. The working portion of the pin is an anti-friction roller I54 the diameter of which equals the narrow portion of the keyhole slot.

The operation of this contact structure will be understood after a study of the wiring diagram in Fig. 7. A two-gang manual selector switch I56, I58 may be provided for controlling the six-position coaxial selector switch heretofore described and a position indicator. Switch I58 has six positions with an indicator lamp I60 at each. Switch I56 also has six tap positions (A, B, F) for connecting through a cable to connector I8 and to the respective axially resilient contacts 38. As illustrated in Fig. 7, the contacts 38 are identified by letters A, B, C, D, E, and F corresponding to the tap positions of the switch I56. Two windings I62 and I64 of motor 82 are arranged for split-phase operation by means of capacitor 84.

When selector contact 26 is in any given position, as adjacent contact 38 (A'), the motor will not be energized provided that the selector arm of switch I56 is in the corresponding position (A). If it is desired to cause an indexing Operation to position B, for example, selector switches I56 and I58 are moved to that position. The motor is then energized. From terminal I66 of the power line to terminal G of connector I8 and junction I68 of windings I62 and I64, one branch circuit extends through winding I64, capacitor 84, contact 40, slip ring 48, lead I32, segment 44, contact 38 (B'), selector I56 and through a relay I10 to line terminal I12. A separate branch of the circuit is established from line terminal I66 and junction I68 through motor winding I62 and contact 40, etc., to line terminal I12.

Relay I10 is energized concurrently with the motor circuit. The relay is provided with a pair of normally closed contacts IT! in series with the lamp circuit. So long as the motor is energized no lamp will light since contacts I11 remain open.

The motor causes indexing not only of selector contact 26, as previously described, but also causes indexing of the commutator segment unit 44, 46, etc. When selector contact 26 is radially projectod at terminal 22 (B), an insulating element I16 or I18 will be opposite contact 38 (B) and the motor will be de-energized. These insulating elements are provided to fill the gaps in track 50 between segments 44 and 46.

The motor is de-energized at the end of each indexing operation in an abrupt manner to prevent pitting of contacts 38 and of segments 44 and 46 at their edges. This is accomplished in the following manner. The initial action of the drive mechanism is to withdraw contact 26 inwardly, thereby carrying roller I54 toward the large diameter portion of keyhole I50 and disc I30. When contact 26 is indexed, in a snapaction initially, the selector assembly 44, 46, etc. lags by a short distance. This indexing travel, in which the lag is caused by the friction of contacts 38 on segments 44 and 46, forces roller I54 against the forward surface of the enlarged portion of keyhole I50. When detent 28 is just about to enter notch 30 (B), contact 38 (B) is still fully engaged with segment 44. Then because of the outward travel of roller I54 in keyhole I50, the contact assembly 44, 46, etc. is sharply indexed to bring insulating element I16 in line with contact 38 (B).

It might be desired to select terminal 22 (C) rather than 22 (B) starting from the (A) position. In that event the motor is not de-energized when the selector assembly moves into position (B). After engaging terminal 22 (B) contact 26 is again retracted and indexed until insulating element I16 is opposite contact 38 (C).

The remote-control system embodies a known arrangement for limiting the number of indexing operations to a minimum from any given starting position to any required destination. The motor circuit described above is for indexing the selector contact 26 and contact assembly 44, 46, etc. clockwise. The motor, however, operates in the reverse direction in indexing from A to F (or D or E). In that event, a different motor circuit is established, which is as follows. Starting with line terminal I66 and junction I68, winding I64 is energized not through capacitor 84 but through contact 42, segment 46, contact 38 (F), selector switch I56, relay I10 and line I12. Wind- 3 ing I62 is energized from terminal I66 and junction I68 through capacitor 84 and contact I42, etc. to terminal I12. With this circuit connection, the motor drive is the reverse of that for indexing the appropriate insulator H4 or I16 from position (A) to (B) or (C).

All of the illustrative circuit conditions described have started with the (A) position, but the principles of operation are the same starting from any of the other positions.

Spring contacts 38 are mounted on an insulating horseshoe-shaped member I which is in turn supported by stud spacers I82 on ring 3!. Member I80 would ordinarily be an annulus, but is relieved opposite connector I8 to accommodate the wiring. When the casing sections are separated, spring contacts 38 no longer bear on segments 44 and 46 and that segment assembly may in that event be readily removed. With the casing sections assembled, however, the combined spring pressure of contacts 38 is transmitted through assembly 44, 46, etc., to plate 98, transition piece 10 and conical element 54. This assures firm contact between this conical element and its seat in terminal 20.

Insulation is not ordinarily provided between the casing and any of the terminals 20 and 22, but it may be added if required by the circuit conditions. Spring contact I84 (Fig. 4) is for the motor and capacitor sub-assembly and is provided for convenience in completing the circuits whenzassembling ;the-.-motor:andareduction gear ing and the wiring tocon-nector. 18.

Summary" The. described coax selectorswitch. which incorporatesna/ radially movable outerconductor in. the selector. assembly has been found; to bev notably effective at ultra-highz-frequencies, having; a.- commendablylow standing-.waveeratio. While amanual-knob on shaft 36 may in. some: uses replace the motor driven; the remote-control feature. as. -added..-forms. :an intimate part of the selector switch. The follow-up: contact arrangee ment is. improved by association with p in:.l52 of the-:radially movable selector contact. The radial motionof thelselector-contact mechanism will be found -.desirab1e.in switches of other than .coax' construction ,.-,and can even lie-advantageous for.

power .frequencies-andfor. direct-current circuits.- Among the many novel features of. this useful switchare: the radiallymovable indexible con tact, especiallyone'that grips its slide bearing as it seats in the selected terminaLand that. is..asso

ciatedwith an inner, coaxial conductor; the resilient loadon the .motor-duringthe start ofindexing. followed by the. positive indexing: drive whereby the motoris not. subjected-to a heavy starting load; and. the interaction between the radially movable selector and the remote -.control.

follow-upcontact assembly, for prevention of arcing atthe follow-upcontacts.

It.is to be understoodthatvarious modificaa tions. and changes can. be made inthis invention without. departing fromnthe spirit and. scope thereof. as set forth inv th'eappendedclaims.

What is claimedlisz- 1. A radio-frequency selectorswitchccmpris.

inga casinghavinga plurality-of. coaxial contact terminals radially disposed thereon, a central coaxial contact member axially disposediwithin-said casing, and. aradially disposed selector contact. member, associated. with said. central contact member and including... a. bearing member, a yieldably retractable outer conductor slidably.

mounted. on saidbearing member, and an inner coaxial. conductor, said-selector contact memberbeing, indexible. to any selected: oneof said axial contact terminals, .andsaid outerv conductor. beingradially retractable preparatory to said'indexing and radially projectablewhen said. se lector. contact member .is. in. the. selected position, thereby to. establish a fim-n. contact with the se-. lectedwcontact terminaL.

2. In combinationinaselector .switch a plu. ralityof. coaxial. terminals. eachlhaving, an inner conductor and an outer. coaxial.memberinsuleited: therefrom,v said outer. coaxial..members...having. an. inner end ..formed to define a. frustoeconical. seat, a. selector. assembly .adaptedto be indexed.

tovanybt said: contact terminals: andhavingeari. inner :conductor, an outer coaxial zbearingqmeme ber insulated; :from" sai-dcin-ner conductor, and' a; sliiiablewcoaxialmember 'embracing;said bearingl memberr and :'hawing;-; a slotted frustoeconicalend; adapted: to be wedged within. the" frusto-conical/ seat-:of, the outer lcoaxial member ofa-said. contact terminals thereby to grip; said bearing :member and .toi-form: azfirmunion between said. selector assembly and the-selected contact terminal, and. means. for yieldably urging gsaid :slidable =:coaxial-. member intoxseatedrelation with said contact ter:-- minal when said. selector assembly is in a selected position.

31na: selector switch for use with. ultra-high.

frequency electromagnetic energy, the combina another of:said-contactterminals.

4; In -.a selector switch, the combination of a rotatively indexible: selector element having; a radially movable-member, and a control system. including driving means, .resilient meanscon 4 meetin said driving means to saidselector ele ment means connected to said driving. means for radiallyretracting saidmovable-member, and for simultaneously ,compressingsaidresilient means, said resilientmeans being operative'upon retrace. tion ofsaid movablemember-to initiate-indexing. 0t saidselector element, and meanspositivelyen-w gaging. said-Idr'ivingmeans and saidse1ector-elementafter saidrinitiating'action, wherebyto com plete said indexing operation NORMAN E? REFERENCES CITED The:following references are ofcrecord in the file ofthiswpatent:

UNITED STATES PATENTS Number Name... Date 2,255,501 Blume Sept..9, 1941 2,318,541.v Tewksbury .May 4,-l1943 2,360,219" Goddard ,Oct. 10, 1944 $405,628 Yardeny Aug. 13. 194.6. 2,409,895. Phelps .Oct. 22,1946- 2,419,30'Z I Zottu r Apr, 22,1947. 

